Sometimes life is particually cruel , and this seems like one of those times. You (both) work hard for decades , scrimp , save , worry , budget , make do , form a plan etc. Then there is the end of the rainbow in sight, you can take your foot off the gas , relax , enjoy what you have effectively earned over the years. Then out of the blue, cancer.
Quick change of plan. Re-evaluate , adapt , crack on .
The outcome is inevitable. The bit in the middle is where you show how caring and respectful you can be . It sounds to me like you did the best you could, given the circumstances. There will be dark days , for sure , but try to remember the best of times. Sorry for your loss TJ.